Three facts about radiometric dating
Most notable is William Thomson, ennobled to become Lord Kelvin in 1892, whose theories make up an entire section of this collection.
He was one of the dominant physicists of his time, the Age of Steam.
Lord Kelvin and his allies used three kinds of argument.
The first of these referred to the rate of heat loss from the earth and the length of time it would have taken to form its solid crust.
It was not until 1926, when (under the influence of Arthur Holmes, whose name recurs throughout this story) the National Academy of Sciences adopted the radiometric timescale, that we can regard the controversy as finally resolved.
One outstanding feature of this drama is the role played by those who themselves were not, or not exclusively, geologists.
The most famous came in 1654, when Archbishop James Ussher of Ireland offered the date of 4004 B. Within decades observation began overtaking such thinking.
In the 1660s Nicolas Steno formulated our modern concepts of deposition of horizontal strata.
The second referred to such topics as the detailed shape of the earth (bulging slightly at the equator) and the dynamics of the earth-moon system.
The third referred to the heat of the sun, particularly the rate at which such heat is being lost, compared with the total amount of energy initially available.